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The best sway bar to get on E46s is the BMW Motorsport 40mm. You can get it from Turner Motorsport for a little over 1k. I heard its what all the fast guys use.

See, here we go with that whole concept of "best" again. What works for one setup can be completely inappropriate for another. Sure, for a dedicated track car running race tires this might be the ultimate sway bar. That's way too much bar for street tires though and would likely lead to some nasty understeer.

Hotchkis bars are somewhat unique since they are tubular and relatively light. KWs have progressive springs. I've found that they tend to roll quite a bit. But body roll isn't necessarily a bad thing. You don't want the car so stiff it becomes twitchy.

I think your first step is to make sure you have fresh bushings in the car. Then choose a good damper/spring combo. Swift springs are supposed to be the new rage. Maybe Bilstein sports with swift springs? I think you'll need new front perches and rear spring mounts.

The problem with KW, whether it be V1, V2, or V3, is the lack of flexibility in spring rates along with their use of progressive rate springs. The dampers are also going to be limited in the range of spring rates they can handle. I really just can't recommend KW for high performance/track driving.

Oh no! So I was thinking about the KW V3's for my street E46 ZHP that I'd like to slowly start converting over to be a little more track focused for the occasional drivers ed event. What really attracted me to those were the remote reservoirs. But I hadn't really considered that progressive springs might not be ideal for my purposes. What would you recommend for a better track-appropriate setup and why, remembering that this will still be mostly driven on the street. Ideally, I'd like to decrease midcorner wallow, and with it, the amount of time the car takes to settle in an S-curve transition. Any recommendations are appreciated.

As for suspension, if you want to go linear and have quality stuff, check out tckline.

btw, if you're just starting out, going to an adjustable shock may be worse if you don't know how to adjust them to get what you want out of them. The V1s are definitely very soft, but as mentioned, v2s still run progressive springs... Another alternative would be groundcontrol adjustable konis with your choice of spring rates.

Oh no! So I was thinking about the KW V3's for my street E46 ZHP that I'd like to slowly start converting over to be a little more track focused for the occasional drivers ed event. What really attracted me to those were the remote reservoirs. But I hadn't really considered that progressive springs might not be ideal for my purposes. What would you recommend for a better track-appropriate setup and why, remembering that this will still be mostly driven on the street. Ideally, I'd like to decrease midcorner wallow, and with it, the amount of time the car takes to settle in an S-curve transition. Any recommendations are appreciated.

Linear rate springs will greatly improve transitions. I can highly recommend AST for a street/track setup followed closely by TC Kline. I've been running my AST 4100 setup for several years now and absolutely love it - it's quite a bit of suspension for the money.

Linear rate springs will greatly improve transitions. I can highly recommend AST for a street/track setup followed closely by TC Kline. I've been running my AST 4100 setup for several years now and absolutely love it - it's quite a bit of suspension for the money.

What kind of dampers do you run with these linear springs, if you don't mind me asking?
For example, could you pair the adjustable and remote reservoir KW V3 dampers with a linear rate spring? Maybe get the best of both worlds?

What kind of dampers do you run with these linear springs, if you don't mind me asking?
For example, could you pair the adjustable and remote reservoir KW V3 dampers with a linear rate spring? Maybe get the best of both worlds?

I wouldn't consider your proposed setup to be "the best of both worlds" by any means. KW isn't total crap but they're not all that great either... there are certainly better options out there for adjustable dampers.

As I mentioned in my last post, I've been running AST 4100 coilovers on my car for several years now. I'm currently running 500 lb/in Hyperco springs up front (and considering a switch to 550#) and 650 lb/in Hyperco springs in the rear. H&R sways are full stiff up front and near full soft in the rear. It's firm but completely streetable - I daily drive my car as it's the only car I own (and the streets around Dallas aren't known for being all that smooth).

The 4100 monotube dampers are single adjustable in rebound only. They also offer a 4200 model which is adjustable for both rebound and compression as well as a 5000 series of dampers which are inverted and offer an upgrade path (ie, 5100 can be upgraded to 5200 and later to 5300). For a street driven car doing the occasional driving event, the 4100 dampers would be far more than adequate. The 4100/4200 dampers also provide enough room to easily run a 255 width tire up front for a square setup (much better for performance than the staggered stock 225/255 setup). Not sure how easy this is with the larger diameter of the 5000 series. Can't go wrong with any of the AST dampers but you really aren't likely to find a need for more than the 4100 unless you are getting into competitive racing. Speaking of racing, AST-USA has recently been chosen as a supplier of dampers for GRAND-AM racing:http://www.vorshlag.com/forums/showt...5743#post55743

Linear rate springs will greatly improve transitions. I can highly recommend AST for a street/track setup followed closely by TC Kline. I've been running my AST 4100 setup for several years now and absolutely love it - it's quite a bit of suspension for the money.

Research has led me to this^ conclusion as well. The only reason I'd go with TC Kline is that they allow you to maintain full stock ride height. And if I went with ASTs I'd probably get them bundled with Swift springs: http://www.hpashop.com/product.sc?pr...categoryId=159

I can get pretty close to stock ride height with my AST setup but I choose run it just slightly lower (I've got some pics posted over in an ARC-8 thread in T&W). Swift makes a good spring but there's no reason to favor them over Hyperco in our application. Swift has simply been over-promoted to the point where they are believed to have near magical qualities....

EDIT: link to pics of my car. I've actually lowered it about 1/2" since these pics were taken.

Swift makes a good spring but there's no reason to favor them over Hyperco in our application. Swift has simply been over-promoted to the point where they are believed to have near magical qualities....

My setup is very similar to TxZHP and SpeedDemon's with AST 4200s and 550/650 springs, with the H&R 30mm (M3) bar up front full stiff and the H&R 21mm bar in the rear full soft. Thinking more spring and no bar in the rear for next year. At least, this is what I run during the summer, I'm finding stock ZHP works best during the winter. (when we're offroading half the time!)

Some feedback on swaybars and soft springs:
- Swaybars actually account for a rather larger percentage of overall roll resistance, especially when talking near-stock spring rates up front.
- The will make the suspension less independent, so a lot of rear bar isn't desired
- They will limit roll while affecting ride comfort less than stiffer springs, so that's why such a large percentage of roll resistance is provided through bars from the factory

Right now I'm running the stock rear bar and the H&R 30mm M3 bar up front on full stiff, on my stock springs and ZHP dampers and 225 snow tires. When I had the 21mm bar on full stiff in the rear, I'd say the handling felt a little "goofy", but with the 30mm still in on full stiff and stock rear, it helps limit roll without overloading the tires, at least in normal commuting driving. I haven't pushed this setup, since there's about 14" of snow on the ground here. =] I can definitely feel turn-in and weight transfer is happening a lot faster than with a smaller bar, but it doesn't seem to be overloading the tires.

The main advantages of the Hotchkis bars is the rear bar will be a bit stiffer, and they're hollow, and so lighter, vs the H&R. Lighter won't matter much if you're not racing.

The H&R 30mm M3 bar is (AFAIK) the stiffest generally available (as in, not crazy motorsports version) front bar, and fits the non-M just fine, though I'm told the rear H&R M3 bar does not fit the non-M.

If you'd like an upgrade from the KW, I'd highly recommend the AST 4100s, they're a high quality damper that will help make relatively stiff springs much more reasonable on the road, but if this is still mainly a street car, here's the setup I'd recommend:
AST 4100s, Vorshlag camber plates, 400/550 spring rates, 30mm H&R bar front, stock rear.

I'm not sure I'd go below 550 for rear spring rate, as the stock springs are progressive from like 350-650.

I run 5100's with ~450 / 570 Swift springs, Vorshlag plates and Eibach sways, I love this setup - superb on track and the street, worlds away from the old Koni sport setup I had.

Quote:

Originally Posted by McSpeed

The only reason I'd go with TC Kline is that they allow you to maintain full stock ride height.

You do have to run AST'S pretty low to get a reasonable amount of droop travel, although AST have now come up with a spacer for for the fronts to allow a higher ride height. Think the rears need one too for a stock ride height.

You do have to run AST'S pretty low to get a reasonable amount of droop travel, although AST have now come up with a spacer for for the fronts to allow a higher ride height. Think the rears need one too for a stock ride height.

Sweet where can I read about this?

UPDATE: response from Vorshlag to "I heard that you have come up with spacers that allow a 2005 330i with 4100s, say, to maintain full stock ride height - is this accurate?"

Quote:

No. Minimum drop is 1" from stock with AST 4100s on that car. Even that is too tall, and we make a new "droop extender" for use with our camber plates and ASTs, to add additional droop into the front suspension, but it does not alter ride height.

I haven't read too much discussion of JRZ or Motons, and I'm curious if that's because of a higher pricepoint being a significant barrier to popular ownership. Maybe they're just too stiff for daily drivers? Opinions?

I don't know much about the megans, FK, or Ksport, (all junk) but the Bilstein, (PSS9?) KW, and H&R aren't really "coilovers", they're matched systems that would take some re-working if you wanted to change springs and in some cases ride height. (but are also good and relatively cheap compromise setups)

Pretty much anything from GC on up are real "coilovers", and to greater or lesser extents can be what you want them to be in terms of street or track use. The more expensive stuff on the list (AST, JRZ, Moton, Ohlins) are more capable of handling higher spring rates, and so they're more track-capable, but that doesn't mean they're less streetworthy, just that it's difficult to justify the expense in a non-competitive use. Most of them, being higher quality systems, are going to have the effect of making stiff springs more comfortable on the street. Or at least, I know the ASTs and Motons will, (and of course both of those have two different lines of dampers with different internals and price points) not totally sure about the JRZs or Ohlins, they may just be valved off the shelf for way too high of spring rate to be street-comfortable, I couldn't say, they're more popular among the club racing crowd.

The GC and TCK are koni-based, and so they'll be relatively comfortable with anywhere from stock to compromise (400 lb?) spring rates, but get less capable of keeping things comfy as the spring rates climb.

Picking the right dampers is tricky, and so that's why TxZHP was asking about use and budget. If you want something that can grow with you as you move from strictly street use into light and then competitive track use, the AST 4100 is a good choice at a good price. If you see your track time being more occasional and less competitive, the KWs, PSS9, or H&R cup kit setup might work well. If you've got money to burn, get yourself some AST 5100s or Motons, and they'll be plenty capable in whatever you want them to do.